Rent to Low Credit Applicants with a Co-signer?

[Jason L.]

I had some applicants apply to one of my listings who seem like nice people but have terrible credit (480). I denied their application for not meeting the minimum qualifications. They are now saying that their parents, who have an 800 credit score and good income, are willing to co-sign on the lease. I don't have any experience with applicants using co-signers on a lease. Is it worth pursuing or should I stick with my gut to deny the application?